ChromeOS EC Keyboard
Google’s ChromeOS EC Keyboard is a simple matrix keyboard implemented on
a separate EC (Embedded Controller) device. It provides a message for reading
key scans from the EC. These are then converted into keycodes for processing
by the kernel.
This binding is based on matrix-keymap.txt and extends/modifies it as follows:
Required properties:
- compatible: “google,cros-ec-keyb”
Optional properties:
- google,needs-ghost-filter: True to enable a ghost filter for the matrix
keyboard. This is recommended if the EC does not have its own logic or
hardware for this.
Example:
cros-ec-keyb {
compatible = “google,cros-ec-keyb”;
keypad,num-rows = <8>;
keypad,num-columns = <13>;
google,needs-ghost-filter;
/*
* Keymap entries take the form of 0xRRCCKKKK where
* RR=Row CC=Column KKKK=Key Code
* The values below are for a US keyboard layout and
* are taken from the Linux driver. Note that the
* 102ND key is not used for US keyboards.
*/
linux,keymap = <
/* CAPSLCK F1 B F10 */
0x0001003a 0x0002003b 0x00030030 0x00040044
/* N = R_ALT ESC */
0x00060031 0x0008000d 0x000a0064 0x01010001
/* F4 G F7 H */
0x0102003e 0x01030022 0x01040041 0x01060023
/* ‘ F9 BKSPACE L_CTRL */
0x01080028 0x01090043 0x010b000e 0x0200001d
/* TAB F3 T F6 */
0x0201000f 0x0202003d 0x02030014 0x02040040
/* ] Y 102ND [ */
0x0205001b 0x02060015 0x02070056 0x0208001a
/* F8 GRAVE F2 5 */
0x02090042 0x03010029 0x0302003c 0x03030006
/* F5 6 - \ */
0x0304003f 0x03060007 0x0308000c 0x030b002b
/* R_CTRL A D F */
0x04000061 0x0401001e 0x04020020 0x04030021
/* S K J ; */
0x0404001f 0x04050025 0x04060024 0x04080027
/* L ENTER Z C */
0x04090026 0x040b001c 0x0501002c 0x0502002e
/* V X , M */
0x0503002f 0x0504002d 0x05050033 0x05060032
/* L_SHIFT / . SPACE */
0x0507002a 0x05080035 0x05090034 0x050B0039
/* 1 3 4 2 */
0x06010002 0x06020004 0x06030005 0x06040003
/* 8 7 0 9 */
0x06050009 0x06060008 0x0608000b 0x0609000a
/* L_ALT DOWN RIGHT Q */
0x060a0038 0x060b006c 0x060c006a 0x07010010
/* E R W I */
0x07020012 0x07030013 0x07040011 0x07050017
/* U R_SHIFT P O */
0x07060016 0x07070036 0x07080019 0x07090018
/* UP LEFT */
0x070b0067 0x070c0069>;
};
